scsi: myrb: Remove unused functions

This was detected by building the kernel with clang and W=1.

Link: https://lore.kernel.org/r/20210415220826.29438-11-bvanassche@acm.org


Cc: Hannes Reinecke <hare@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>